In preparing silver halide photographic materials, coloration of photographic emulsion layers and other layers is often affected for the purpose of absorbing light within a particular wavelength range.
For the purpose of preventing the halation or blurring of a photographic image to be formed in a photographic material (which is caused by re-introduction of light passing through the photographic emulsion layer or scattering after passing through said photographic emulsion layer into the photographic emulsion layer after reflection by the interface between the emulsion layer and the support or by the surface of the material which is opposite to the emulsion layer), a colored layer is often provided between the photographic emulsion layer and the support or on the surface of the support which is opposite to the photographic emulsion layer. Such a colored layer is called an anti-halation layer.
In X-ray photographic materials, a colored layer is often provided for the purpose of improving the sharpness as a crossover-cutting filter capable of reducing the crossover light to be introduced into the material.
Such a colored layer is mostly made of a hydrophilic colloid. For coloration of the layer, a dye(s) is/are incorporated into the layer. Potential dyes to be used for this purpose must satisfy the following conditions:
(1) The dyes must have a suitable spectral absorbability in accordance with the use and object.
(2) The dyes must be photo-chemically inactive. That is, they do not have any bad chemical influences on the photographic property of silver halide photographic emulsion layers constituting the photographic material; for instance, they do not lower the sensitivity and do not cause latent image fading and fogging.
(3) The dyes are decolored or dissolved and then removed in the step of photographic processing the photographic materials containing them so that they do not leave any harmful coloration in the processed photographic materials.
Where a colored layer such as an anti-halation layer or a crossover-cutting layer is made of a hydrophilic colloid, it results in an increase of the bulk of the water-permeable layer such that the drying property of the photographic material during development is disadvantageously worsened.
In order to overcome this drawback, fixation of dye(s) in a layer to be provided between a hydrophilic colloid layer and a support so as to elevate the adhesiveness between them is accomplished.
The layer having a function of sticking a support and a hydrophilic colloid layer to each other is herein called a subbing layer. There are many methods for fixing dye(s) in such a subbing layer; for example, there is: a method of adsorbing dye(s) to a mordant agent in the subbing layer (JP-A-1-126645) (the term "JP-A" as used herein means an "unexamined published Japanese patent application"); a method of emulsifying and dispersing an oily solution of dye(s) in the subbing layer in the form of oily drops (JP-A-1-142688); a method of adsorbing dye(s) on surfaces of inorganic substances in the subbing layer (Japanese Patent Application No. 1-139691 corresponding to JP-A-3-5748); a method of adsorbing dye(s) to a polymer in the subbing layer (JP-A2-298939); and, a method of directly dispersing solid dye(s) as they are in the subbing layer (Japanese Patent Application No. 1-87367 corresponding to JP-A-2-264936).
Of these methods, preferred is the method of directly dispersing solid dye(s) as they are in a subbing layer since the dye(s) may be fixed in a determined layer, and the processed photographic material has little residual color caused by the incorporated dye(s).
The amount of hydrophilic colloid to be used in a subbing layer is generally small; for example, 0.5 g/m.sup.2 or less.
Where a dye dispersed in the form of fine solids grains is introduced into such a hydrophilic colloid layer, the film itself, as coated with the layer, would thereby be more brittle so that the surface of the coated layer could easily be scratched. The optical density of the dye in the scratched area is to be lower than that in the normal area.
The scratched area having such a lowered optical density is to have an increased crossover light, which would therefore have harmful influences on the photographic properties of the photographic material. In addition, if the scratched dust adheres to the base of the material, the dust-adhered area is to have a decreased crossover light and would also have harmful influences on the photographic properties of the same.
As mentioned above, decreasing the scratch-resistance of the surface of the coated subbing layer is a serious problem.